Differential expression of acetylcholinesterase molecular forms in neural retina and retinal pigmented epithelium during chick development.

Neural retina (NR) and retinal pigmented epithelium (RPE) were used as a model for studying acetylcholinesterase (AChE) expression in neuronal and non-neuronal tissues during development. In chick embryo retina, increasing AChE activity appeared from day 7 to hatching, first in NR and then in RPE. NR contained 3 main AChE forms, 11.3S, 6.5S and 4.5S, resolved by sucrose density gradient centrifugation. An additional 19S form was exclusively detected in RPE whatever the extraction procedure followed. During differentiation, the proportions of AChE molecular form changed until they reached a steady state characteristic of mature neural retina, whereas in RPE, patterns of AChE molecular forms did not change significantly during development. Thus, 19S AChE appeared to be characteristic of non-neuronal retinal tissue. The expression of the AChE molecular forms in NR and RPE, and particularly the 19S form, was independent of the presence of the lens during retinal differentiation.